TNF and sensorineural hearing loss disorder: In a previous in vivo study on TNF-α-induced intracochlear cytotoxicity, Keithley et al. (53) investigated whether the mechanism underlying TNF-α-induced SNHL may involve TNF-α-induced recruitment of circulatory leukocytes to the inner ear, as it is known that the inner ear's rapid inflammatory response to antigen/pathogen invasion can cause hearing loss and irreversible damage to the inner ear's mechanosensory structures (54, 55).